title: Biological control of crown gall of grapevine, rose, and tomato by nonpathogenic Agrobacterium vitis strain VAR03-1.
abstract: A nonpathogenic strain of Agrobacterium vitis VAR03-1 was tested as a biological control agent for crown gall of grapevine (Vitis vinifera). When roots of grapevine, rose (Rose multiflora), and tomato (Lycopersicon esculentum) were soaked in a cell suspension of antagonists before planting in soil infested with tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens, respectively, treatment with VAR03-1 significantly reduced the number of plants with tumors and disease severity in the three plant species. The inhibitory effects of treatment with VAR03-1 and the nonpathogenic A. rhizogenes strain K84 on crown gall of rose and tomato were almost identical, and the inhibitory effect of VAR03-1 on grapevine was superior to that of K84. Moreover, VAR03-1 greatly controlled crown gall of grapevine due to tumorigenic A. vitis in the field. VAR03-1 established populations averaging 10(6) colony forming units (CFU)/g of root in the rhizosphere of grapevine and persisted on roots for 2 years. VAR03-1 was bacteriocinogenic, producing a halo of inhibition against those three species of Agrobacterium. This is the first report that a nonpathogenic strain, VAR03-1, can effectively control crown gall caused by tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens.
authors.affiliation: Laboratory of Plant Pathology and Entomology, Agricultural Experiment Station, Okayama Prefectural General Agriculture Center, Okayama, Japan. akira_kawaguchi@pref.okayama.lg.jp
authors.forename: A
authors.initials: A
authors.lastname: Kawaguchi
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: Y
authors.initials: Y
authors.lastname: Ichinose
mesh_terms: D016960:Agrobacterium tumefaciens / Q000254:growth & development / Q000502:physiology; D000898:Antibiosis; D018551:Solanum lycopersicum / Q000382:microbiology*; D010941:Plant Tumors / Q000382:microbiology*; D012231:Rhizobium / Q000254:growth & development* / Q000502:physiology; D027826:Rosa / Q000382:microbiology*; D027843:Vitis / Q000382:microbiology*